Capacitive touch sense unit computation power reduction using keypad electrodes crosstalk

摘要

A touch sensitive capacitive keypad system (300) is provided with a keypad sensing electrode (304) disposed within sensing proximity of multiple electrodes (E0-E9) and formed under a keypad touch panel having defined key areas, where the electrodes are respectively aligned with the defined key areas to facilitate touch detection at the keypad touch panel with a controller (310) that is configured to determine which of the plurality of defined key areas is being touched by detecting a predetermined signal characteristic at the keypad sensing electrode (304) before sequential scanning the plurality of capacitive key electrodes to identify which capacitive key electrode is aligned with a defined key area being touched.